This is the nose of the Gemini XII spacecraft as photographed by Buzz Aldrin. He was standing up on his seat with his hatch open while orbiting at 8,000 meters per second 188 miles over the Earth. I wish I were able to imagine the sensation of what this felt like.

This is the Lunar Module Systems Activation Checklist Book of Apollo 13. The handwritten numbers are part of the calculations made by Commander James Lovell, just two hours after a service module's oxygen tank explosion left them marooned in space.